Apparatus for working sheet metal



June 25, 1935. R. J. MlLLER 2,006,087

APPARATUS FOR WORKING SHEET METAL Filed ma 3, 1930 5 Sheets-Sheet 2 gnwntoz 1 47/ PAL PH d M/LLEQ I QQMM June 25, 1935. R, J. MILLER APPARATUS FOR WORKING SHEET METAL Filed May 5, 1930 5 Sheerls-Sheet 3 M 5:- m 9N 3====== ,9 N mm i June 25, 1935. R. J. MILLER 2,006,037

APPARATUS FOR WORKING SHEET METAL Filed May 5, I930 5 Sheets-Sheet 4 /0 A9 I ammo,

June 25, 1935. J MlLLER 2,006,087

APPARATUS FOR WORKING SHEET METAL Filed May 3, 1.930 5 Sheets-Sheet 5 mmuuw:

gwuento r Patented June 25, 1935 2,006,087

UNITED STATES PATENT OFFICE APPARATUS FOR WORKING SHEET METAL Ralph J. Miller, Youngstown, Ohio, assignor to The McKay Machine Company, Youngstown, Ohio, a corporation oi Ohio Application May 3, 1930, Serial No. 449,609

1: Claims. (01. 153-54) This invention relates to a sheet metal working speed than the feed rolls to transmit a tensioning apparatus, and more particularly to a machine action to the sheet as it passes between such sets ior treating metal sheets to remove stretcher of rolls, the apparatus being provided with sheet strains and for other purposes. bending means operative upon the sheet between 5 Certain of the processes involved in the manuthe feed rolls and the pulling rolls. 7 5

facture of steel and other metal sheets efiect the A further object is to provide an apparatus stretching of the sheets beyond their normal wherein a metal sheet is adapted to be subjected yielding limit, under which conditions certain to a tensioning action and simultaneously to a strains are developed which produce surface bending action to remove stretcher strains from 10 blemishes in the sheets, commonly known as the sheet and to provide means for adjusting the 10 stretcher strains. degree of tension to which the sheet is subjected An important object of the present invention during the bending operation. is to provide an apparatus which is operative for A further object is to provide an apparatus of effectively removing stretcher strains from metal the character above referred to having novel sheets. means for rendering the sheet bending means 15 A further object is to provide an apparatus of operative after the sheet has progressed a predethe character referred to which is adapted to subtermined distance through the apparatus, and ject a sheet to a series of alternate bends in diffor returning the bending means to normal posiferent directions while moving through the aption as the sheet passes from the apparatus.

paratus, to minimize stretcher strains in the A further object is to provide an apparatus of 20 sheets. the character referred to which is efficient not A further object is to provide an apparatus for only for removing stretcher strains from sheets, removing stretcher strains from sheets by bendbut which is also readily adapted for use for reing the sheet during its passage through the moving buckles, bulges, coil breaks, or any other machine, and for subjecting the sheet to a tenunevenness from sheet or strip metal. 25 sioning action while undergoing the bending op- Other objects and advantages of the invention eration. will become apparent during the course of the A further object is to provide an apparatus of following description. the general character referred to which is oper- In the drawings I have shown one embodiment ative, if desired, for providing strips or sheets of of the invention. In this showing, 30

metal with irregular ornamental surfaces adapt- Figure 1 is a plan view of the apparatus,

ed for making finished articles which may be Figure 2 is a transverse section taken subleft plain or may be surface coated. stantially on line 22 of Figure 1 showing the A further object is to provide an apparatus of sheet bending rolls in inoperative position, parts the character just referred to which is operative being omitted for the purpose of illustration, 35 for bending a strip or sheet and subjecting it dur- Figure 3 is a sectional view similar to Figure 2 me u h bending 0 8 Stretching tion which showing the bending rolls in operative position, causes the metal of the strip or sheet to be Figure 4 is an elevation of one end of the apstretched slightly beyond its yield point whereby t 40 the resultant sheet will be provided with an ir- Figure 5 is a section on line 5-5 of Figure 1, 40 regular crinkled surface Somewhat resembling Figure 6 is an elevation of the other end of the long grgin leather, for ornamental purposes. apparatus,

A further object is to provide an apparatus, Figure 7 is a section on line of Figure 1, having sheet bending means which is normally Figure 8 is a similar View on line H of my is inoperative to permit the sheet to be readily ure 1 inserted into the apparatus, and to provide means for rendering the sheet bending means auto g 9 is slmflar View on line of m8- 1 matically operative after the entering end of a sheet has progressed to a given point in its travel Figure 10 1s sectlon taken substantially on through the apparatus. Figure 50 A furth object is to provide a sheet comm Figure 11 1s a detail vertical sectional view 11- tionjng apparatus having a pair of feed 11 t lustrating the sheet bending means and associated the entrance end of the apparatus and a plurality elements, parts being h wn in vfl i of pulling rolls adjacent the outlet end, the pull- Figure 12 is a detail section on line ll-II of V ing rolls being rotatable at a somewhat higher Figure l, 66

Figure 14 is a' detail elevation illustrating the metal treating roll locking means and the brake operating cam,

Figure 15 is a diagrammatic view of the electrical connections of the apparatus, and,

Figure 16 is a plan view of a fragment of a strip or sheet treated with the apparatus and in accordance with the method to provide an ornamental sheet surface.

Referring to Figures. 1 and 10, the numerals Iii and ii designate a pair of relatively heavy supports spaced from and parallel to each other and adapted to rotatably support a plurality of rolls to be referred to in detail later. The supports i and I I, as well as other elements of the apparatus to be described are mounted upon a suitable base i 2.

A pair of feed rolls i3 are arranged adjacent the inlet end of the apparatus and are adapted to initially engage the entering ends of sheets fed into the apparatus in a manner to be described. The feed rolls are provided with trunnions i4 the lower of which are mounted in bearings l5 mounted in a slot l6 formed in the supports i3 and H. The upper trunnions H are journalled in bearing blocks i'! which are also mounted in the slot i6 and are vertically adjustable therein. The adjusting means includes upwardly extending screws l8 to be referred to.

The lower portions of the supports it) and ii are connected by braces is, as clearly shown in Figure III. A cap member indicated as a whole by the numeral 20 connects the tops of the supports I0 and II. As shown, the cap member com= prises a pair of parallel side members 2i secured against the tops of the supports, and these members are connected to each other by a bridge 22.

The parallel members 2i are provided with openings slidably receiving the screws i8, the upper ends of which are threaded in worm wheels 23 meshing with worms 24 carried by a shaft 25 extending transversely across the tops of the supports. The shaft 25 is supported in any suitable form of bearings carried by the members 2l. A hand wheel 26 is adapted to rotate the shaft 25, and thus transmit rotating movement to the worm 23 to move the screws l8, and coning yokes 33.

sequently the bearing blocks l1, vertically according to the thickness of the sheets to be fed between the rolls I3. The adjusting means may be of any desired character and forms no part of the present invention.

Beneath the bridge 22 are mounted a plurality of pairs of upper and lower pulling rolls 21, as shown in Figure 4. The path of movement of the sheet between the upper and lower pulling rolls forms a continuation of the path of the sheet between the feed rolls I 3. The feed rolls l3 are spaced a substantial distance from the adjacent pairs of pulling rolls 21, for a purpose to be described. The pulling rolls 2'! are provided at their ends with trunnions 28, and the trunnions of the lower rolls are journalled in bearing blocks 29 mfallfied in slots 30 formed in the supports in an in vertically slidable bearing blocks in the slots 30.

A plurality of lower pressure rolls 32 contact with the bottom portions of the lower pulling rolls 21, and the pressure rolls are journalled in bear- The pressure rolls serve to support the lower pulling rolls against any possible flexing thereof when under pressure.

3i mounted Theupper trunnions 28 are journalled A plurality of similar pressure rolls 34 is mounted to engage the upper portions of the upper pulling rolls 21. The rolls 34 are journailed in depending bearing arms 35 carried by yokes 36 which are movable downwardly to adjust the maximum space between the upper and lower rolls 2! so as to cause these rolls to tightly engage the sheets passing therebetween. The yokes 36 are provided with a plurality of upstanding rods or stems 31 which are threaded at their upper ends for engagement in gears 38. The rods 37 and their associated gears 38 are arranged in adjacent pairs and the gears of each pair are connected to each other by an intermediate gear 33 carried by a shaft 40.

The upper end of each shaft 46 is provided with a worm wheel 4! meshing with a worm 42 secured to a shaft 43. This shaft is journalled in suitable bearings 44 mounted on top of the bridge 22. One end of the shaft 43 is provided with a hand wheel 45 which is adapted to be rotated to rotate the worms 42 and worm wheels 4!. This rotating movement is transmitted to the gears through the intermediate gears 39, thus imparting movement to the rods 37 and yokes 36 to vary the space between the upper and lower rolls 2? for the purpose described. The adjusting means described forms no part of the present invention and any suitable adjusting means may be employed. It will be apparent that the pressure rolls 34 also function in the same manner as the pressure rolls 32 to prevent any upward flexing of the upper feeding rolls 21.

Means are provided between the rolls it? and the adjacent rolls 2'! for bending the sheets as they pass through the apparatus. Referring to Figures 2' and 3, the numerals 46 and 41 designate a pair of metal working rolls which are normally arranged in the position shown in Figure 2. The metal working rolls are preferably spaced apart a distance substantially greater than the thickness of the sheet as shown. This space, when the metal working rolls are in normal position, is arranged in the same horizontal plane as the spaces between the upper and lower rolls i3 and the upper and lower rolls 2! as shown in Figure 2.

The ends of the rolls 46 and 4'! are provided with trunnions 48 joumalled in plates 49, as shown in Figure 11. Relatively heavy trunnions 50 are carried by the plates 49 and project outwardly therefrom in axial alinement with each other. The axis of the trunnions 50 lies parallel to and midway between the axes of rotation of the rollers 46 and 41. -As shown in Figure 10, the trunnions 50 are journalled in bearings 60 carried by the supports l0 and II.

A counter shaft Si is mounted below the metal working rolls 46 and 41, and has its axis parallel thereto. The shaft Si is .journalled in bearings 62 carried by the supports I0 and i I, as shown in Figure 10, and outwardly of each of the supports, the shaft 6| is provided with pinions 63 meshing with gears 64 carried by the extremities of the trunnions 50. In the embodiment of the invention illustrated, the gears 64 are twice the diameter of the pinions 63, whereby rotation of the shaft 6| through a. half revolution is adapted to simultaneously rotate the plates 49 through a quarter circle about the axis of the trunnions 50. When this action takes place, in a manner to be described, the metal working rolls will be swung from the inoperative position shown in Figure 2 to the operative position illustrated in Figure 3.

Shown n F gures and 11, means is pro- Vl for ho ding the metal working rolls 46 and 41 in operative position by preventing reverse transmitting current to the contact 95, and in rotation of the plates 49. Pawls are pivotally connected to the supports I0 and II. and are adapted to eng e the teeth of eachgear 04 after the latter have been rotated by the shaft GI, and accordingly it will be apparent that the shafts 50 can be rotated only in one direction. For a purpose to be described, the outer end of the shaft 6| is provided with a cam 80.

As shown in Figure l, the base I2 extends a substantial distance to one side of the various rolls and associated elements described, and a supporting structure indicated as a whole by the numeral 61 is mounted upon the projecting portion of the base. The supporting structure 91 includes a plurality of vertical members designated generally by the reference numeral 00, and these vertical members are provided with a number of bearings, which need not be referred to in detail, to support a number of shafts to be described.

The inner trunnion associated with each of the pulling rolls 21 is provided with a driving connection 99, illustrated in Figure 1 as comprising a relatively heavy flat plate having enlarged end portions of substantially semicircular cross section adapted to be connected to the shafts with which they are associated. The driving members 09 are respectively connected to the inner ends of shafts I0 and 'I I, arranged in alinement with the upper rolls 21, and similar parallel shafts I2 and I3 arranged in alinement with the lower rolls 21. Similarly, the inner trunnions cf the feed rolls I3 are connected by driving members I4 to upper and lower shafts I5 and I9 arranged respectively in alinement with the upper and lower feed rolls. The shafts I5 and I0 are connected together to be simultaneously driven by gears It. The various shafts referred to are v:Iournalled in suitable bearings carried by the supporting structure 01.

Beyond the supporting structure 01, the base I2 is transversely-enlarged as at H, and supports a suitable motor I8 forming a power source for the apparatus. The motor shaft carries a driving pinion l9 meshing with a gear 00 carried by a shaft 8i, and this shaft is 'journalled in a suitable bearing 92 carried by the base. The gear fit meshes with a similar gear 83 carried by a shaft 84 journalled in a bearing 85.

The shaft iii is provided with cushion means for driving certain of the elements of the apparatus. Referring to Figures 1 and 12,- the numerals 8i and 8] designate a pair of relatively rotatable members, the former of which is keyed or otherwise secured to the shaft 8i, as indicated at 88. The member 80 is provided with a pair of projecting arms 89, and these arms provide seats for one end of each of a pair of springs 90, which may be of any desired type. The opposite ends of the springs seat against projections 9i extending laterally from the adjacent face of the member 81. It will beapparent that the springs provide cushion driving means for transmitting rotative forces from the member 86 to the member 81.

One of the arms 99 projects a substantial distance beyond the periphery of the member 81, as indicated at 92, and is provided on one side with a contact 93. The member 91 is provided with a radial projection 94 carrying a suitably insulated contact 95 adapted to engage the contact 93 when the latter moves to the dotted line position shown in Figure 12, under conditions to be referred to later. Any suitable means may be employed for Figure 1 the rotatable member 81 is illustrated as being provided with a contact ring 96 engaged by a suitably supported brush 91.

The rotatable member 81 is carried by a shaft 90 suitably journalled in the adjacent portion of the structure 61, and the shaft 98 carries a driving pinion 99. A gear I00 meshes with the pinion 99 and is carried by the shaft I2 as shown in Figure 6. Referring to Figures 1 and 9, the numeral IOI designates a gear carried by the shaft I2 and meshing with a similar gear I02 carried by the shaft II. Accordingly it will be apparent that rotation of the shaft I2 is transmitted to the shaft II and these shafts rotate in opposite directions. The shaft I0 terminates at the point I03 (see Figure 1) and at a point spaced from its extremity, this shaft is provided with agear I04 meshing with a similar gear I05 carried by the shaft I2, as shown in Figure 7. Accordingly it will be apparent that the shaft I0 will be driven by the shaft I2, to which power is transmitted in the manner referred to above. Similarly, the shaft 'II carries a gear I00 meshing with a gear I01 carried by the shaft I3, and accordingly the latter shaft will be driven from the shaft II. It will be apparent from the driving connections just described that the pulling rolls will be constantly driven as long as the motor I8 is in operation, but it also will be apparent that a suitable clutch may be provided as, for example, in the shaft 8| to stop the rotation of the pulling rolls when desired.

As shown in Figures 1 and 9, the shaft I3 also carries a pinion I08 meshing with an idler gear I 09 freely rotatable on the shaft 6| previously described. The gear I09, in turn, meshes with a gear H0. This gear is secured to a. cylindrical member III carrying a spring pressed pawl H2, as shown in Figure 9, and this pawl is adapted to engage the teeth of a ratchet H3 carried by the shaft I8. -It will be apparent that rotation of the member III by the gear Ill) will drive the shaft I8 in one direction. As will become apparent, thepawl H2 prevents reverse rotation of the shaft I6, but permits the latter to rotate at a greater rate of speed than the member iii, for a purpose to be described.

Referring to Figures 1 and 5, it will be noted that means is provided for transmitting power from the shaft st to the shaft iii arranged in alinement therewith. In the drawings, a planetary transmission has been illustrated, but it will be apparent that any form of transmission means may be employed. A gear H0 is carried by the shaft 80 and meshes with a series of planetary gears I I5, these gears in turn meshing with a sun or ring gear 6 it formed within a drum Ill. The pinions H5 are rotatably supported by trunnions H8 carried by a spider H9, as shown in Figures 5 and 11. The spider H9 is provided with a hub I20 connected to the shaft 6|.

A cam wheel I2I is mounted on the hub I20, and is provided with diametrically opposite depressions I22 each of which has one side substantially radially arranged as at I23 and its opposite side slightly sloping as at I24. The cam wheel is provided at diametrically opposite points with contacts I25 shown diagrammatically in Figure 15, but it will be apparent that these contacts are arranged to one side of the cam wheel in order that the highpoints or' cylindrical portions I25 of the cam wheel may be free for a purpose to be described. I

Referring to Figures 5 and 8, the numeral I21 designates a lever arm connected to a shaft I29 and provided at its upper end with a roller I29 adapted to engage the cam wheel I2I The lower end of the lever I21 is connected as at I39 to the outer end of a bar I3I forming the armature of a solenoid I32. It will be apparent that energization of the solenoid I32 is adapted to swing the lower end of the lever I21 inwardly to free the roller I29 from either of the cam depressions I22 in which it may be arranged.

A source of current I33 is provided for the solenoid I32. One terminal of the source is connected to one end of the winding of the solenoid by a wire I34, while the opposite end of the solenoid is connected by a wire I35 to a brush arm I36, adapted to engage one of the contacts I25. A similar brush I31 also is adapted to engage one of the contacts I25 to afford electrical connection between the brushes, and the brush I31 is connected by a wire I38 to the contact 95'of the cushion driving means described. The other terminal of the source is connected to the contact 93 by a wire I39.

Movement of the lever arm I21, upon energization of the solenoid I32, is utilized for preventing rotation of the drum I I1 to render the planetary transmission operative. Referring to Figure 5, it will be noted that the shaft I28 is Journalled in bearings I40, and this shaft carries a depending arm I4I connected to one end of a push rod I42. The free end of the rod I42 extends through a guide I43. A brake band I44 surrounds the drum H1 and is provided with a suitable lining I45 adapted to engage the drum H1. The free ends of the band I44 are provided with lugs I46 and I41. the former of which engages against the guide I43 which serves as a stop for the lug. A coil spring I48 surrounds the rod I42 and abuts the lugs I46 and I41 and a nut or collar I49 is carried by the rod I42 to engage against the outer face of the lug I41. It will be apparent that outward swinging movement of the upper end of the lever I 21 is adapted to move the lug I41 inwardly, thus bringing the brake band into engagement with the drum II1 to prevent rotation thereof.

As previously stated, the ratchet driving means illustrated in Figure 9 is adapted to rotate the shaft 16 at a fixed maximum speed, although the shaft is adapted to be rotated at a higher speed than that imparted to it by the ratchet means. However, braking means is provided for limiting the speed of rotation of the shaft 18 when the latter overruns the ratchet tooth II2. Referring to Figures 4, and 11, the numeral I59 designates a. brake drum carried by the outer trunnion I4 of the lower feed roll l3. This drum is adapted to be engaged by a brake band I5I having a fixed lug I52 connected to one end thereof. A movable lug I53 is carried by the opposite end of the brake band and is pivotally connected as at I54 to one end of a lever I55. This lever is pivotally connected intermediate its ends as at I56 to one end of a rod I51, extending 'h ough the fixed lug I52 and a spring I58 surrounds the rod I51 and tends to urge the ends of the brake band away from each other.

A roller I59 is carried by the free end of the lever I55 and engages against the cam 66 previously described. A spring I68 is operative to pull the free end of the lever I55 inwardly to retain the roller I59 in engagement with the cam 66.

The operation of the apparatus is as follows: The pulling rolls 21 are simultaneously rotated at equal speeds through the gearing connections previously described. Attention is invited to the fact that the drive from the motor passes through the cushion driving means, and when no sheets are passing through the apparatus, no resistance will be ofiered to the rotation of the rolls 21, and hence the springs 90 will be in a substantially open position, whereby the relatively rotatable members 66 and 81 and the contacts 93 and 95 will occupy the relative positions shown in solid lines in Figure 12. The metal working rolls 46 will be in the inoperative position illustrated in Figure 2, and the contact arms I36 and I31 will occupy the normal position shown in Figure 15.

I in engagement with one of the contacts I25.

As previously stated, the feed rolls I3 are constantly driven through the medium of the gears I08, I99 and H0, and the ratchet driving means illustrated in Figure 9. The speed of rotation of the feed rolls I3, however, is materially less than the speed of rotation of the pulling rolls 21, this difference in speed being determined by the driving gearing of the several rolls. The rolls I3 are properly spaced to permit the entrance therebetween of the entering end of a sheet of a given thickness in order that the rolls I3 may positively drive the sheets," and the rolls 21 are similarly arranged so as to tightly engage the sheet.

The sheet is interposed between the rolls I3 and is advanced thereby between the rolls 46 and 41, which do not initially engage the sheet, after which the sheet comes into engagement with the first pair of rolls 21. The greater speed of rotation of the rolls 21 tends to pull the sheet faster than the linear speed of the rolls I3, and resistance to the rotation of the rolls 21 is accordingly introduced. This resistance is transmitted to the various shafting and gearing employed for rotating the rolls 21, and thus will be transmitted to the cushion driving means illustrated in Figure l2.

As previously stated, the contacts 93 and 95 normally occupy the position shown in solid lines in Figure 12, and when resistance to the rotation of the rolls 21 is introduced relative rotation is imparted to the members 86 and 81 with the resuit that the contact 93 moves across the contact 95 to assume the dotted line position illustrated in Figure 12. Referring to Figure 15, it will be apparent that the circuit for the solenoid I32 will be completed, while the contacts 93 and 95 are in engagement with each other, and during this interval the solenoid will retract its armature, thus swinging the lever I 21 about its pivot to move the roller I29 free of the associated cam notch I22, and at the same time, the rod I42 will be pushed inwardly to apply the brake against the drum II1.

Rotation of the drum II1 will be prevented under the conditions stated, and thus rotation of the gear II4 will effect rotation of the pinions H5, and accordingly the spider I I9, and thus rotating movement is transmitted in turn to the shaft 6|. As soon as the shaft 6| starts to rotate it moves the cam disk I2I, and the cam notch I22 in which the roller I29 previously rested will pass beyond the roller and the latter will be supported upon the cylindrical or high point of the cam wheel, thus retaining the brake in operative position after the contact 93 passes beyond the contact 95, and after the contact I25 has passed from beneath the brushes I36 and I31.

Under the conditions referred to, it will be apparent that the cam wheel I2I will be rotated through a half revolution, at the completion of which the roller I will drop into the next cam notch I22 to release the brake from the drum H1. The rotation of the shaft BI is imparted to the plates 49 through the gears 82 and 54, and thus the metal working rolls 48 and 41 will be revolved. As previously stated, the diameter of the gear 54 is double the diameter of the gear 63. and since the cam wheel I2I will have moved through half a revolution, it will be apparent that the plates 49 and associated elements will be retated through a quarter circle about the axis of the trunnions 58. The rollers 46 and 41 and the elements connected thereto constitute in efiect, a reel which will be rotated automatically in the manner referred to upon the entrance of the sheet between the rolls 21, to cause the rolls 46 and 41 to assume the positions shown in Figure 3.

As previously stated, the shaft 18 is adapted to overrun the pawl tooth II2, but the brake I5I (see Figure) is adapted to limit the overrunning movement. Upon rotation of the shaft 6| in the manner previously described, the cam 58 will be brought into engagement with the roller I59, thus moving the lever I55 to apply the brake I5I against the drum I50. The nut on the rod I51 is adapted to adjust the brake so that the resistance of the latter against the drum I50 may be varied as desired. Accordingly it will be apparent that since the sheet will be tightly engaged both by the rolls I3 and the rolls 21, and that since these sets of rolls rotate at differential speeds, the sheet will be subjected to a tensioning action as it passes through the apparatus.

It will be noted that when the reel swings to operative position, it takes up considerably on the length of the sheet, and the brake is released during such operation so as to prevent placing on the sheet such a tension as to cause the breaking thereof. The brake is automatically brought into operation however, as the reel approaches operative position. The resistance offered to the movement of the sheet as it enters between the pulling rolls is suflicient to operate the relatively movable members of the cushion drive for the purpose stated.

It will be apparent that the tension of the sheet will tend to movethe rollers 46 and 41 to turn the reel back to normal position, and after the reel has been moved to operative position, the pawl 55 (see Figure 14) will prevent reverse rotation of the reel by engaging the teeth of the gear 54. In this connection it may be stated that while the reel is illustrated as being adapted to turn through a quarter circle to operative position, the degree of turning movement may be varied according to the position of the cam notches I22. Under any conditions, however, the rollers 45 and 41 will be projected through the path of the sheet at an equal extent from opposite sides thereof.

When the cam wheel I2I is turned to the operative position described, the brushes I35 and I31 will come into engagement with the other contact I25, and obviously will remain in such position during the passage of the sheet through the apps.- ratus. At the same. time it will be apparent that the brush 93 will be retained in the dotted line position illustrated in Figures 12 and 15, since the play between the relatively rotatable members 86 and 81 will be constantly taken up while the sheet is passing through the apparatus. As soon as the sheet has passed beyond the rolls I3, 45 and 41, the resistance against the rotation of the rolls 21 will be released, and accordingly the contact 93 will return to operative position.

previously described. The lever I21 again will be actuated to lift the roller I28 from the second cam notch I22, and to apply the brake against the drum 1, whereupon rotation again will be imparted to the shaft BI to return the reel to normal position.

Two sets of the pulling rolls 21 have been illustrated, but any number may be employed as desired. It will be noted that these rolls operate in the same manner as the usual leveling apparatus, and accordingly. the sheets, after being treated to remove the stretcher strains, will be levelled by the rolls 21 and will be discharged from the apparatus substantially flat.

From the foregoing it will be apparent that the present apparatus provides novel means for bending a sheet of metal during its movement through the apparatus by projecting the metal working rolls through the plane of movement of the sheet to an equal extent from opposite sides thereof and this action is very effective for eliminating stretcher strains. The differential rotation of the rolls I3 and 21 imparts a tensioning action to the sheet simultaneously with the bending action, and it has been found that this tensioning action materially increases the efficiency of the apparatus to remove stretcher strains, thus providing a resultant sheet of remarkably uniform internal and surface structure. The sheet is thus materially improved in quality, and results in a corresponding improvement in the quality of the products manufactured therefrom.

The apparatus is also operative for providing certain classes of strips or sheets with ornamental surfaces. For example, it has been found that if strips or sheets of cold rolled mild steel are passed through the apparatus, the surfaces of such strips or sheets will be provided with ornamental surfaces somewhat similar to long grain leather, as illustrated in Figure 15 of the drawings. This result is believed to be due to the breaking of the hard surface structure of strips or sheets of the character referred to, and provides a very attractive surface which may be left plain and polished, or may be coated with suitable surface coating compositions.

The invention has been described above particularly with reference to its application for removing stretcher strains from sheet metal. In the manufacture of sheet metal, however, stretcher strains are not the only difficulty encountered. For example, finished metal sheets are often buckled or bulged at different points in their surfaces, and it is desired to remove this unevenness. Furthermore, in the manufacture of strip metal, it is the'common practice to wind the strips on reels, and when these strips are unwound, they bend rather sharply transversely of the strips at spaced points therealong, such bends being commonly known in the industry as coil breaks. It has been found that any unevenness in a sheet or strip of metal of the character referred to readily may be removed by passing the sheet or strip through the apparatus in accordance with the method disclosed above.

It is to be understood that the form of the invention herein described is to be taken as a preferred example of the same and that various changes in the size, shape and arrangement of parts may be made without departing from the spirit of the invention or the scope on! the subjoined claims.

I claim:

1. Apparatus of the character described comprising upper and lower feed rolls, upper and lower pulling rolls spaced from said feed rolls and defining therewith a path of travel for a sheet passing between said rolls, means for driving all of said rolls whereby mid pulling rolls rotate at a. greater rate of speed than said ieed rolls, sheet working members arranged between said feed rolls and said pulling rolls respectively above and below the normal path of travel of the sheet, and means for projecting said sheet working members through the normal plane of the sheet to an equal extent on opposite sides thereof.

7 2. Apparatus of the character described comprising upper and lower feed rolls, upper and lower pulling rolls spaced from said feed rolls and defining therewith a path of travel for a sheet pass ing between said rolls, a pair of sheet working rolls arranged between said feed rolls and said pulling rolls and adapted to project respectively upwardly and downwardly through the normal plane of the sheet, and means for subjecting the sheet transversely of said sheet working rolls to a tensioning action greater than is efiected by said sheet working rolls.

3. Apparatus oi the character described comprising upper and lower feed rolls, upper and lower pulling rolls spaced from said feed rolls and defining therewith a. path of travel for a sheet passing between said rolls, means for driving all of said rolls whereby said pulling rolls rotate at a greater rate of speed than said feed rolls, a pair of sheet working rolls arranged between said feed rolls and said pulling rolls and normally disposed in. inoperative position respectively above and below the normal path of travel of the sheet,

and means for projecting said sheet working rolls respectively upwardly and downwardly through the normal plane of the sheet.

4. Apparatus of the character described comprising upper and lower feed rolls, upper and lower pulling rolls spaced from said feed rolls and defining therewith a path of travel for a sheet passing between said rolls, a reel arranged between said feed rolls and said pulling rolls and rotatable about an axis coincident with the plane of the sheet, said real including a pair of metal working rolls equidistantly spaced on opposite sides of the axis of said reel and normally disposed respectively above and below the normal path of travel of the sheet, means for rotating said reel through a partial revolution to project said metal working rolls to operative position through the normal plane of the sheet to an equal extentfromopposite sides thereof, and means for subjecting the sheet transversely of said metal rolls when the latter are in operative position to a tensloning action greater than is efiected by said metal working rolls.

5. Apparatus of the character described comprising upper and lower feed rolls, upper and lower pulling rolls spaced from said feed rolls and. defining therewith a path of travel for a sheet passing between said rolls, means for driving all of said rolls whereby said pulling rolls rotate at a greater rate of speed than said feed rolls, a reel arranged between said feed rolls and said pulling rolls and including a pair of metal working rolls normally arranged above and below the normal path of travel of the sheet, the axis of rotation of said reel being substantially coinci dent with the plane of the sheet, and means for rotating said reel through a partial revolution to project said metal working rolls through the normal plane of the sheet to an equal extent from opposite sides thereof.

6. Apparatus of the character described comprising upper and lower feed rolls, upper and lower pulling rolls spaced from said feed rolls and delining therewith a path of travel for a sheet passing between said rolls, means for driving all oi said rolls whereby said pulling rolls rotate at a greater rate of speed than said feed rolls, a reel arranged between said feed rolls and said pulling rolls and rotatable about an axis coincident with the plane of the sheet, said reel including a pair oi metal working rolls equidistantly spaced on oppo'e,

, site sides of the axis of said reel and normally disposed respectively above and below the normal path of travel of the sheet, and means for rotating said reel through a partial revolution to project said metal working rolls through the normal plane of the sheet to an equal extent from opposite sides thereof.

7. Apparatus of the character described com prising upper and lower feed rolls between which a sheet is adapted to be introduced from one side thereof, upper and lower pulling. rolls spaced from the opposite side of said feed rolls and be-. tween which the sheet is adapted to travel, means for driving all of said rolls whereby said pulling rolls rotate at a greater rate of smed than said feed rolls, sheet working members normally arranged respectively above and below the path of travel of the sheet between said feed rolls and said pulling rolls, and means operative upon engagement of the sheet by said pulling rolls for projecting said sheet working members through the plane of the sheet on opposite sides thereof.

8. Apparatus of the character described comprising upper and lower feed rolls between which a sheet is adapted to be introduced from one side thereof, upper and lower pulling rolls spaced from the opposite side of said feed rolls and be-. tween which the sheet is adapted to travel, means for driving said pulling rolls at a greater rate oi speed than said feed rolls whereby the sheet will be subjected to a tensioning action, a pair of sheet working rolls arranged between said feed rolls and said pulling rolls and normally disposed respectively above and below the plane of the sheet, and means operative upon the subjection of the sheet to the tensioning action for projecting said sheet working rolls respectively upwardly and downwardly through the normal plane of the sheet.

9. Apparatus of the character described comprising upper and lower feed rolls between which a sheet is adapted to be introduced from one side thereof, upper and lower pulling rolls spaced from the opposite side of said feed rolls and between which the sheet is adapted to travel, means for driving said pulling rolls at a greater rate of speed than said feed rolls whereby the sheet will be subjected to a tensioning action, a reel arranged between said feed rolls and said pulling rolls and rotatable about an axis coincident with the plane of the sheet, said reel including a pair of metal working rolls equidistantly spaced on opposite sides of the axis of said reel and normally disposed respectively above and below the normal path of travel of the sheet, and means operative upon the subjection of the sheet to the tensioning action for rotating said reel through a partial revolution to project said metal working rolls to operative position through the normal plane of the sheet to an equal extent from opposite sides thereof.

10. Apparatus constructed in accordance with claim 6 provided with a power source for rotating said teed rolls and said pulling rolls, the means for rotating said reel including a cushion driving device between said source and said pulling rolls operative when the turning movement of said pulling rolls is resisted by the entrance therebetween of the sheet to effect turning movement of said reel.

11. Apparatus of the character described comprising upper and lower feed rolls, upper and lower pulling rolls spaced from said feed rolls and defining therewith a path of travel for a sheet passing between said rolls, a pair of sheet working rolls arranged between said feed rolls and said pulling rolls and normally disposed respectively above and below the normal path of travel of the sheet, means for projecting said sheet working rolls respectively upwardly and downwardly through the normal plane of the sheet to an equal extent, means operative during the operation of said last named means for tensioning the sheet substantially at right angles to said working rolls, and means for varying the amount of tension placed on the sheet.

12. Apparatus of the character described comprising upper and' lower feed rolls, upper and lower pulling rolls spaced from said feed rolls and defining therewith a path of travel for a sheet passing between said rolls, a pair of sheet working rolls arranged between said feed rolls and said pulling rolls and normally disposed respectively above and below the normal path 01' travel of the sheet, means for projecting said sheet working rolls respectively upwardly and downwardly through the normal plane of the sheet to an equal extent, means for driving said feed rolls and said pulling rolls at diilferential speeds to tension the sheet passing therebetween during the operation of said last named means, and means for retarding the speed of rotation of said teed rolls to vary the tension of the sheet.

13. Apparatus oi! the character described comprising upper and lower feed rolls, upper and lower pulling rolls spaced from said teed rolls and defining therewith a path of travel for a for retarding the overrunning speed of said teed rolls.

14. Apparatus constructed in accordance with claim 13 provided with means automatically op-v erative upon movement of said metal working rolls to operative position for rendering said brake efiective.

15. Apparatus constructed in accordance with claim 13 provided with a power source for driving said Ieed rolls and said pulling rolls, the means for projecting said metal working rolls to operative position including a pair of relatively movable members constituting part of a cushion drive device between said power source and said pulling rolls and operative when moved relatively in one direction for projecting said metal working rolls to operative position.

16. Apparatus constructed in accordance with claim 13 provided with a power source for driving said feed rolls and said pulling rolls, the means for projecting said metal working rolls to operative position including a pair of relatively movable members constituting part of a cushion drive device and operative upon the entrance of the sheet between said pulling rolls for projecting said metal working rolls to operative position, and means automatically operative upon movement of said metal working rolls to operative position for rendering said brake eifective.

1'7. Apparatus of the character described comprising upper and lower feed rolls, upper and lower pulling rolls spaced from the feed rolls and defining therewith a path of travel for a sheet passing between said rolls, sheet working means arranged between said feed and pulling rolls and adapted to project through the normal plane of the sheet to subject it to a progressive bending action, means for subjecting the sheet to a tensioning action transversely of the sheet working rolls, and means for varying the degree of tension to which the sheet is subjected.

18. Apparatus of the character described comprising upper and lower feed rolls, upper and lower pulling rolls spaced from said feed rolls and defining therewith a normal path of travel for a sheet passing between said rolls, means for positively driving said pulling rolls, means including an overrunning clutch for driving said feed rolls at a slower rate of speed than said pulling rolls, sheet working means arranged between said ieed and pulling rolls and normally arranged out oi the normal path oi. travel of the sheet, means for projecting said sheet working means through the normal path of travel of the sheet to subject the latter to a progressive bending action between said feed and pulling rolls, and a brake for retarding the overrunning speed of said teed rolls,

RALPH J. MILLER. 

